#include<stdio.h>

int flag = 0;
//int flag = 1;
//int flag = -1;

//求和 a ~ b
int GetSum(int s, int e){
  int result = 0;
  for(int i = s; i <= e; ++i){
    result += i;
  }
  return result * flag;
}

int main(){
  int begin = 0, end = 100;
  printf("The Sum Will be Added from %d to %d\n", begin, end);
  int result = GetSum(begin, end);
  printf("The result is %d, [%d <-> %d]\n", result, begin, end);
  return 0;
}
